Accuracy of oil palm root length measuring methods

• Autor(a) principal: Glória,Gerson C. P.
• Data de Publicação: 2020
• Outros Autores: Amador,Juciene T., Vasconcelos,Steel S.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://scielo.pt/scielo.php?script=sci_arttext&pid=S0871-018X2020000100081
• topic: Elaeis guineensis; image analysis; ImageJ; line-intersect method; Safira

Abstract Length is an important variable to describe root architecture and growth, but root length (RL) measurement is extremely laborious and time-consuming. Image analysis methods can provide reliable and fast RL estimates; such tools have not been applied for oil palm, a globally relevant commodity. We tested two image analysis softwares (Safira and ImageJ) and the modified line-intersect method to estimate oil palm RL. We considered the manual measurement of RL as reference to infer about the accuracy of the image analysis and line-intersect methods. We sampled roots in an 10-yr-old oil palm plantation in eastern Amazon. We used the estimates from the image analysis to calculate a correction factor that was further applied to improve the RL estimates. We applied the Paired sample t-test (p<0.05) to separately test the original and corrected estimates of each method in relation to the reference. Although the original RL estimates of the image analysis and line-intersect showed limited accuracy, the correction factors improved the estimates of RL for ImageJ. We conclude that the ImageJ software is sufficiently accurate to estimate oil palm root length when specific root diameter correction factors are applied.